I bought a Delta Bass 300 head and cab (1x15", 1x8" + horn) the other year, mainly because it was going cheap and local.
I can get a decent sound out of it but I'm still not exactly sure what all the controls do so feel I could be missing out on something.
I've searched the interwebs and there's very little info on these - made by Carlsbro and Overwater in the 80's, didn't sell well so not many about.
There's mention of programmable EQ, compressor, active bass and treble EQ.

Here's some of the controls.....
Gain - I know what this does, there's a little light next to it labelled PPI flickers when turned up, obviously that's clipping.

Bass, Mid Shape, Treble - Obviously some sort of EQ but these go from min to max rather than -10 to +10 (or whatever values) and there's a Mid Select switch by the Mid Shape, assume it changes what mid frequency is altered?

There's also an FX loop with a level control, dry to wet, but even at wet the FX are not 100%, there's still a clean signal there too.

Anti-feedback knob?????

Any info would be gratefully received.
Carlsboro's Delta Bass amplifiers seem to have been popular in the U.K. - certainly more so than in the U.S. The anti-feedback control is exactly that: it is designed to automatically reduce feedback. Set it to "Zero" if you are experiencing no feedback, or adjust it is much as necessary to control your feedback.

Your EQ knobs go from minimum to maximum because they are basic, passive controls (like those found on most amps). The Mid-Shape knob is probably nothing more than a fast mid-scoop control; not necessary if your amp has a Graphic EQ (IIRC, The Delta Bass 300 does have a 9-Band Graphic EQ), but it is faster.

If your pedals are not coming through properly in the FX Loop, then you might want to forget the loop and front-load any pedals you are using.

Hope this helps.
"Maybe this world is another planet's hell?" - Aldous Huxley
Thanks for that, pretty much what I thought.

I'm not using the FX loop as it's virtually useless the way it's working at the moment, seems a strange feature to have as it is.

Was hoping someone might have owned one years ago and know exactly what all the controls did..........